Extra large SF glyphs

There are some Apple widgets (like the Weather Stand-by widget) that use some extra large versions of numbers. In those cases, they appear to be using some modified version of the number glyphs that is much more pleasing to look at. The default corners are very sharp, but rounded makes the letters overall bubbly. With this mystery difference, the overall letters are scare but the corners have a radius. I have been completely unable to replicate this.. Can anyone please point me to how these alternate symbols can be used? It is driving me crazy that this exists but I can't access them.

In the CarPlay video they talk about SF being a variable font, that can adjust boldness, italics, roundedness etc with arbritary values. I did not research how deep you have to go down in the font system, but that seems to be the way to do this. Those glyphs are not a special font, but a different set of those variable parameters.

Extra large SF glyphs
 
 
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